Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 23
Filter
1.
Journal of Organizational and End User Computing ; 34(6):1-17, 2022.
Article in English | ProQuest Central | ID: covidwho-1994276

ABSTRACT

In response to the COVID-19 outbreak, the governments of different countries adopted, such as locking down cities and restricting travel and social contact. Online health communities (OHCs) with specialized physicians have become an important way for the elderly to access health information and social support, which has expanded their use since the outbreak. This paper examines the factors influencing elderly people’s behavior in terms of the continuous use of OHCs from a social support perspective, to understand the impact of public health emergencies. Research collected data from March to April 2019, February 2020, and August 2021, in China. A total of 189 samples were collected and analyzed by using SmartPLS. The results show that (1) social support to the elderly during different stages has different influences on their sense of community and (2) the influence of the sense of community on the intention to continuously use OHCs also seems to change over time. The results of this study provide important implications for research and practice related to both OHCs and COVID-19.

2.
mSphere ; : e0021122, 2022 Jul 12.
Article in English | MEDLINE | ID: covidwho-1938010

ABSTRACT

The innate interferon (IFN) response constitutes the first line of host defense against viral infections. It has been shown that IFN-I/III treatment could effectively contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in vitro. However, how SARS-CoV-2 survives through the innate antiviral mechanism remains to be explored. Our study uncovered that human angiotensin-converting enzyme 2 (ACE2), identified as a primary receptor for SARS-CoV-2 entry, can disturb the IFN-I signaling pathway during SARS-CoV-2 infection in human lung cells. We identified that ACE2 was significantly upregulated by SARS-CoV-2 and Sendai virus (SeV) infection, and exogenous expression of ACE2 suppressed IFN-I production in a dose-dependent manner. Mechanistically, ACE2 disrupted poly (I:C)-mediated inhibition of SARS-CoV2 replication by antagonizing IFN-I production by blocking IRF3 phosphorylation and nuclear translocation. Moreover, ACE2 quenched the IFN-mediated antiviral immune response by degrading endogenous STAT2 protein, inhibiting STAT2 phosphorylation and nuclear translocation. Interestingly, IFN-inducible short ACE2 (dACE2 or MIRb-ACE2) can also be induced by virus infection and inhibits the IFN signaling. Thus, our findings provide mechanistic insight into the distinctive role of ACE2 in promoting SARS-CoV-2 infection and enlighten us that the development of interventional strategies might be further optimized to interrupt ACE2-mediated suppression of IFN-I and its signaling pathway. IMPORTANCE Efficient antiviral immune responses against SARS-CoV-2 infection play a key role in controlling the coronavirus diseases 2019 (COVID-19) caused by this virus. Although SARS-CoV-2 has developed strategies to counteract the IFN-I signaling through the virus-derived proteins, our knowledge of how SARS-CoV-2 survives through the innate antiviral mechanism remains poor. We herein discovered the distinctive role of ACE2 as a restraining factor of the IFN-I signaling in facilitating SARS-CoV-2 infection in human lung cells. Both full-length ACE2 and truncated dACE2 can antagonize IFN-mediated antiviral response. These findings are key to understanding the counteraction between SARS-CoV-2 pathogenicity and the host antiviral defenses.

3.
Front Immunol ; 13: 851642, 2022.
Article in English | MEDLINE | ID: covidwho-1933645

ABSTRACT

The rapid evolution of highly infectious pathogens is a major threat to global public health. In the front line of defense against bacteria, fungi, and viruses, antimicrobial peptides (AMPs) are naturally produced by all living organisms and offer new possibilities for next-generation antibiotic development. However, the low yields and difficulties in the extraction and purification of AMPs have hindered their industry and scientific research applications. To overcome these barriers, we enabled high expression of bomidin, a commercial recombinant AMP based upon bovine myeloid antimicrobial peptide-27. This novel AMP, which can be expressed in Escherichia coli by adding methionine to the bomidin sequence, can be produced in bulk and is more biologically active than chemically synthesized AMPs. We verified the function of bomidin against a variety of bacteria and enveloped viruses, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), herpes simplex virus (HSV), dengue virus (DENV), and chikungunya virus (CHIKV). Furthermore, based on the molecular modeling of bomidin and membrane lipids, we elucidated the possible mechanism by which bomidin disrupts bacterial and viral membranes. Thus, we obtained a novel AMP with an optimized, efficient heterologous expression system for potential therapeutic application against a wide range of life-threatening pathogens.


Subject(s)
COVID-19 , Viruses , Adenosine Monophosphate , Animals , Antimicrobial Peptides , Antiviral Agents/pharmacology , Cattle , SARS-CoV-2
4.
J Med Virol ; 94(10): 4809-4819, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1898903

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the seventh member of the coronavirus family that can infect humans. Recently, more contagious and pathogenic variants of SARS-CoV-2 have been continuously emerging. Clinical candidates with high efficacy and ready availability are still in urgent need. To identify potent anti-SARS-CoV-2 repurposing drugs, we evaluated the antiviral efficacy of 18 selective estrogen receptor modulators (SERMs) against SARS-CoV-2 infection. Six SERMs exhibited excellent anti-SARS-CoV-2 effects in Vero E6 cells and three human cell lines. Clomifene citrate, tamoxifen, toremifene citrate, and bazedoxifene acetate reduced the weight loss of hamsters challenged with SARS-CoV-2, and reduced hamster pulmonary viral load and interleukin-6 expression when assayed at 4 days postinfection. In particular, bazedoxifene acetate was identified to act on the penetration stage of the postattachment step via altering cholesterol distribution and endosome acidification. And, bazedoxifene acetate inhibited pseudoviruses infection of original SARS-CoV-2, Delta variant, Omicron variant, and SARS-CoV. These results offer critical information supporting bazedoxifene acetate as a promising agent against coronaviruses.


Subject(s)
COVID-19 , SARS-CoV-2 , Antiviral Agents/pharmacology , COVID-19/drug therapy , Humans , Indoles , Selective Estrogen Receptor Modulators/pharmacology
5.
Eur J Immunol ; 52(8): 1308-1320, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1825936

ABSTRACT

Human nasal mucosa is susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and serves as a reservoir for viral replication before spreading to other organs (e.g. the lung and brain) and transmission to other individuals. Chronic rhinosinusitis (CRS) is a common respiratory tract disease and there is evidence suggesting that susceptibility to SARS-CoV-2 infection differs between the two known subtypes, eosinophilic CRS and non-ECRS (NECRS). However, the mechanism of SARS-CoV-2 infection in the human nasal mucosa and its association with CRS has not been experimentally validated. In this study, we investigated whether the human nasal mucosa is susceptible to SARS-CoV-2 infection and how different endotypes of CRS impact on viral infection and progression. Primary human nasal mucosa tissue culture revealed highly efficient SARS-CoV-2 viral infection and production, with particularly high susceptibility in the NECRS group. The gene expression differences suggested that human nasal mucosa is highly susceptible to SARS-CoV-2 infection, presumably due to an increase in ACE2-expressing cells and a deficiency in antiviral immune response, especially for NECRS. Importantly, patients with NECRS may be at a particularly high risk of viral infection and transmission, and therefore, close monitoring should be considered.


Subject(s)
COVID-19 , Rhinitis , Sinusitis , Chronic Disease , Humans , Nasal Mucosa/metabolism , Rhinitis/complications , Rhinitis/metabolism , SARS-CoV-2 , Sinusitis/complications , Sinusitis/metabolism
6.
J Virol ; 96(4): e0157821, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1759290

ABSTRACT

The ongoing SARS-CoV-2 pandemic poses a severe global threat to public health, as do influenza viruses and other coronaviruses. Here, we present chimpanzee adenovirus 68 (AdC68)-based vaccines designed to universally target coronaviruses and influenza. Our design is centered on an immunogen generated by fusing the SARS-CoV-2 receptor-binding domain (RBD) to the conserved stalk of H7N9 hemagglutinin (HA). Remarkably, the constructed vaccine effectively induced both SARS-CoV-2-targeting antibodies and anti-influenza antibodies in mice, consequently affording protection from lethal SARS-CoV-2 and H7N9 challenges as well as effective H3N2 control. We propose our AdC68-vectored coronavirus-influenza vaccine as a universal approach toward curbing respiratory virus-causing pandemics. IMPORTANCE The COVID-19 pandemic exemplifies the severe public health threats of respiratory virus infection and influenza A viruses. The currently envisioned strategy for the prevention of respiratory virus-causing diseases requires the comprehensive administration of vaccines tailored for individual viruses. Here, we present an alternative strategy by designing chimpanzee adenovirus 68-based vaccines which target both the SARS-CoV-2 receptor-binding-domain and the conserved stalk of influenza hemagglutinin. When tested in mice, this strategy attained potent neutralizing antibodies against wild-type SARS-CoV-2 and its emerging variants, enabling an effective protection against lethal SARS-CoV-2 challenge. Notably, it also provided complete protection from lethal H7N9 challenge and efficient control of H3N2-induced morbidity. Our study opens a new avenue to universally curb respiratory virus infection by vaccination.


Subject(s)
COVID-19/prevention & control , Influenza A Virus, H7N9 Subtype/immunology , Influenza Vaccines , Orthomyxoviridae Infections/prevention & control , SARS-CoV-2/immunology , Animals , COVID-19/epidemiology , COVID-19/genetics , COVID-19/immunology , /immunology , Female , HEK293 Cells , Humans , Influenza A Virus, H7N9 Subtype/genetics , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Influenza Vaccines/pharmacology , Mice , Mice, Inbred BALB C , Mice, Inbred ICR , Mice, Transgenic , Orthomyxoviridae Infections/epidemiology , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , Pandemics , SARS-CoV-2/genetics
7.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-308214

ABSTRACT

Background: Hydroxychloroquine (HCQ) and chloroquine (CQ) have been widely used for the treatment of the coronavirus disease 2019 (COVID-19), despite limited clinical evidence and controversial early reports. The aim of this report was to provide a systematic review of the literature and meta-analysis on the use of HCQ/CQ with respect to safety and clinical efficacy of these medications. Methods: : We performed a systematic search of the medical databases and included studies if they focused on patients with COVID-19 who received HCQ or CQ alone, or in combination with other treatments, and were compared with a control group. We analyzed two important clinical objectives;viral clearance rate by reverse transcription-polymerase chain reaction (RT-PCR) negativity and all-cause mortality. Results: : A total of 14 studies were included in the quantitative synthesis. The use of HCQ/CQ was associated with higher viral clearance rate compared with control group (OR: 3.12, 95% CI: 2.17-4.49 p<0.0001). In the sensitivity analysis, the effect on viral clearance disappeared (OR 1.44, 95% CI: 0.87-2.37, p=0.155). The use of HCQ/CQ was associated with a higher risk of mortality (OR 1.26, 95% CI: 1.05-1.51, p<0.0001). Due to huge heterogeneity between the studies ( I 2 = 86%, p < 0.01), we performed a meta regression analysis. Both treatment within 24 hours (p=0.047) and comorbidities [hypertension (p=0.025), diabetes (p=0.049) and chronic lung disease (p=0.0064)] contributed to the heterogeneity. HCQ/CQ daily dose (p=0.61) and age (p=0.62) had no impact on effect size. Higher rate of comorbidities led to a higher risk of mortality by using HCQ/CQ. Overall, the use of HCQ/CQ resulted in longer QTc intervals. Conclusions: : Our meta-analysis did not reveal a clinical benefit of HCQ/CQ on in-hospital outcomes for patients with COVID-19. The use of HCQ/CQ did not result in rapid viral clearance on RT-PCR. Moreover, our results showed that higher rate of comorbidities led to a higher risk of mortality by using HCQ/CQ.

8.
Journal of inflammation research ; 15:851-864, 2022.
Article in English | EuropePMC | ID: covidwho-1688114

ABSTRACT

Purpose Plant polyphenols possess beneficial functions against various diseases. This study aimed to identify phenolic ingredients in Camellia fascicularis (C. fascicularis) and investigate its possible underlying anti-inflammatory mechanism in lipopolysaccharide (LPS)-induced human monocytes (THP-1) macrophages. Methods C. fascicularis polyphenols (CFP) were characterized by ultra-performance liquid chromatography (UPLC) combined with quadrupole-time-of-flight mass/mass spectrometry (Q-TOF-MS/MS). The THP-1 cells were differentiated into macrophages under the stimulation of phorbol 12-myristate 13-acetate (PMA) and then treated with LPS to build a cellular inflammation model. The cell viability was detected by CCK-8 assay. The levels of reactive oxygen species (ROS) were assessed by flow cytometry. The secretion and expression of inflammatory cytokines were tested by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR). In addition, the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were analyzed by Western blotting. Results Twelve phenolic constituents including (–)-epicatechin, casuariin, agastachoside, etc. in CFP were identified. The CCK-8 assay showed that CFP exhibited no significant cytotoxicity between 100 and 300 μg/mL. After treated with CFP, the release of ROS was significantly suppressed. CFP inhibited inflammation in macrophages by attenuating the polarization of LPS-induced THP-1 macrophages, down-regulating the expression of the pro-inflammatory cytokines IL-6, IL-1β and TNF-α, and up-regulating the expression of the anti-inflammatory cytokine IL-10. Western blotting experiments manifested that CFP could markedly inhibit the phosphorylation of p65, ERK and JNK, thereby suppressing the activation of NF-κB and MAPK signaling pathways. Conclusion These findings indicated that CFP exerted anti-inflammatory activity by inhibiting the activation NF-κB and MAPK pathways which may induce the secretion of pro-inflammatory cytokines. This study offers a reference for C. fascicularis as the source of developing natural, safe anti-inflammatory agents in the future.

9.
Sci China Life Sci ; 65(6): 1181-1197, 2022 06.
Article in English | MEDLINE | ID: covidwho-1596898

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global crisis. Clinical candidates with high efficacy, ready availability, and that do not develop resistance are in urgent need. Despite that screening to repurpose clinically approved drugs has provided a variety of hits shown to be effective against SARS-CoV-2 infection in cell culture, there are few confirmed antiviral candidates in vivo. In this study, 94 compounds showing high antiviral activity against SARS-CoV-2 in Vero E6 cells were identified from 2,580 FDA-approved small-molecule drugs. Among them, 24 compounds with low cytotoxicity were selected, and of these, 17 compounds also effectively suppressed SARS-CoV-2 infection in HeLa cells transduced with human ACE2. Six compounds disturb multiple processes of the SARS-CoV-2 life cycle. Their prophylactic efficacies were determined in vivo using Syrian hamsters challenged with SARS-CoV-2 infection. Seven compounds reduced weight loss and promoted weight regain of hamsters infected not only with the original strain but also the D614G variant. Except for cisatracurium, six compounds reduced hamster pulmonary viral load, and IL-6 and TNF-α mRNA when assayed at 4 d postinfection. In particular, sertraline, salinomycin, and gilteritinib showed similar protective effects as remdesivir in vivo and did not induce antiviral drug resistance after 10 serial passages of SARS-CoV-2 in vitro, suggesting promising application for COVID-19 treatment.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Cricetinae , HeLa Cells , Humans
10.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296091

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is highly contagious and causes lymphocytopenia, but the underlying mechanisms are poorly understood. We demonstrate here that heterotypic cell-in-cell structures with lymphocytes inside multinucleate syncytia are prevalent in the lung tissues of coronavirus disease 2019 (COVID-19) patients. These unique cellular structures are a direct result of SARS-CoV-2 infection, as the expression of the SARS-CoV-2 spike glycoprotein is sufficient to induce a rapid (approximately 45.1 nm/sec) membrane fusion to produce syncytium, which could readily internalize multiple lines of lymphocytes to form typical cell-in-cell structures, remarkably leading to the death of internalized cells. This membrane fusion is dictated by a bi-arginine motif within the polybasic S1/S2 cleavage site, which is frequently present in the surface glycoprotein of most highly contagious viruses. Moreover, candidate anti-viral drugs could efficiently inhibit spike glycoprotein processing, membrane fusion, and cell-in-cell formation. Together, we delineate a molecular and cellular rationale for SARS-CoV-2 pathogenesis and identify novel targets for COVID-19 therapy.

11.
Proc Natl Acad Sci U S A ; 118(50)2021 12 14.
Article in English | MEDLINE | ID: covidwho-1555255

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), binds to host receptor angiotensin-converting enzyme 2 (ACE2) through its spike (S) glycoprotein, which mediates membrane fusion and viral entry. However, the expression of ACE2 is extremely low in a variety of human tissues, especially in the airways. Thus, other coreceptors and/or cofactors on the surface of host cells may contribute to SARS-CoV-2 infection. Here, we identified nonmuscle myosin heavy chain IIA (MYH9) as an important host factor for SARS-CoV-2 infection of human pulmonary cells by using APEX2 proximity-labeling techniques. Genetic ablation of MYH9 significantly reduced SARS-CoV-2 pseudovirus infection in wild type (WT) A549 and Calu-3 cells, and overexpression of MYH9 enhanced the pseudovirus infection in WT A549 and H1299 cells. MYH9 was colocalized with the SARS-CoV-2 S and directly interacted with SARS-CoV-2 S through the S2 subunit and S1-NTD (N-terminal domain) by its C-terminal domain (designated as PRA). Further experiments suggested that endosomal or myosin inhibitors effectively block the viral entry of SARS-CoV-2 into PRA-A549 cells, while transmembrane protease serine 2 (TMPRSS2) and cathepsin B and L (CatB/L) inhibitors do not, indicating that MYH9 promotes SARS-CoV-2 endocytosis and bypasses TMPRSS2 and CatB/L pathway. Finally, we demonstrated that loss of MYH9 reduces authentic SARS-CoV-2 infection in Calu-3, ACE2-A549, and ACE2-H1299 cells. Together, our results suggest that MYH9 is a candidate host factor for SARS-CoV-2, which mediates the virus entering host cells by endocytosis in an ACE2-dependent manner, and may serve as a potential target for future clinical intervention strategies.


Subject(s)
COVID-19/virology , Myosin Heavy Chains/metabolism , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/metabolism , Cell Line , Cell Membrane/metabolism , Humans , Lung/metabolism , Middle East Respiratory Syndrome Coronavirus/physiology , Myosin Heavy Chains/chemistry , Myosin Heavy Chains/genetics , Protein Binding , Protein Domains , SARS Virus/physiology , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
12.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293601

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is highly contagious and causes lymphocytopenia, but the underlying mechanisms are poorly understood. We demonstrate here that heterotypic cell-in-cell structures with lymphocytes inside multinucleate syncytia are prevalent in the lung tissues of coronavirus disease 2019 (COVID-19) patients. These unique cellular structures are a direct result of SARS-CoV-2 infection, as the expression of the SARS-CoV-2 spike glycoprotein is sufficient to induce a rapid (approximately 45.1 nm/sec) membrane fusion to produce syncytium, which could readily internalize multiple lines of lymphocytes to form typical cell-in-cell structures, remarkably leading to the death of internalized cells. This membrane fusion is dictated by a bi-arginine motif within the polybasic S1/S2 cleavage site, which is frequently present in the surface glycoprotein of most highly contagious viruses. Moreover, candidate anti-viral drugs could efficiently inhibit spike glycoprotein processing, membrane fusion, and cell-in-cell formation. Together, we delineate a molecular and cellular rationale for SARS-CoV-2 pathogenesis and identify novel targets for COVID-19 therapy.

13.
Cell Res ; 31(12): 1230-1243, 2021 12.
Article in English | MEDLINE | ID: covidwho-1475291

ABSTRACT

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the ongoing global pandemic that poses substantial challenges to public health worldwide. A subset of COVID-19 patients experience systemic inflammatory response, known as cytokine storm, which may lead to death. Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is an important mediator of inflammation and cell death. Here, we examined the interaction of RIPK1-mediated innate immunity with SARS-CoV-2 infection. We found evidence of RIPK1 activation in human COVID-19 lung pathological samples, and cultured human lung organoids and ACE2 transgenic mice infected by SARS-CoV-2. Inhibition of RIPK1 using multiple small-molecule inhibitors reduced the viral load of SARS-CoV-2 in human lung organoids. Furthermore, therapeutic dosing of the RIPK1 inhibitor Nec-1s reduced mortality and lung viral load, and blocked the CNS manifestation of SARS-CoV-2 in ACE2 transgenic mice. Mechanistically, we found that the RNA-dependent RNA polymerase of SARS-CoV-2, NSP12, a highly conserved central component of coronaviral replication and transcription machinery, promoted the activation of RIPK1. Furthermore, NSP12 323L variant, encoded by the SARS-CoV-2 C14408T variant first detected in Lombardy, Italy, that carries a Pro323Leu amino acid substitution in NSP12, showed increased ability to activate RIPK1. Inhibition of RIPK1 downregulated the transcriptional induction of proinflammatory cytokines and host factors including ACE2 and EGFR that promote viral entry into cells. Our results suggest that SARS-CoV-2 may have an unexpected and unusual ability to hijack the RIPK1-mediated host defense response to promote its own propagation and that inhibition of RIPK1 may provide a therapeutic option for the treatment of COVID-19.


Subject(s)
COVID-19/pathology , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/drug therapy , COVID-19/mortality , COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Cytokines/genetics , Cytokines/metabolism , Down-Regulation/drug effects , ErbB Receptors/metabolism , Humans , Imidazoles/pharmacology , Imidazoles/therapeutic use , Indoles/pharmacology , Indoles/therapeutic use , Lung/pathology , Lung/virology , Mice , Mice, Transgenic , Mutation , Receptor-Interacting Protein Serine-Threonine Kinases/antagonists & inhibitors , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Survival Rate , Transcriptome/drug effects , Viral Load/drug effects , Virus Internalization
14.
Emerg Microbes Infect ; 10(1): 1555-1573, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1324547

ABSTRACT

To curb the pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), multiple platforms have been employed toward a safe and highly effective vaccine. Here, we develop a novel cell-based vaccine candidate, namely K562-S, by utilizing human cell K562 as a cellular carrier to display Spike (S) protein of SARS-CoV-2 on the membrane. Analogous to the traditional inactivated vaccine, K562-S cells can be propagated to a large scale by culturing and completely lose their viability after exposure to X-ray irradiation or formalin. We in turn demonstrated high immunogenicity of formalin-inactivated K562-S vaccine in both mouse and non-human primates and its protective efficacy in mice. In mice, immunization with inactivated K562-S vaccines can elicit potent neutralizing antibody (nAb) responses persisting longer than 5 months. We consequently showed in a hACE2 mouse model of SARS-CoV-2 infection that a two-shot vaccination with adjuvanted K562-S rendered greater than 3 log reduction in viral lung load and concomitant ameliorated lung pathology. Of importance, the administration of the same regimen in non-human primates was able to induce a neutralizing antibody titer averaging three-fold higher relative to human convalescent serum. These results together support the promise of K562-based, S-protein-expressing vaccines as a novel vaccination approach against SARS-CoV-2. Importantly, with a powerful capacity to carry external genes for cell-based vectors, this platform could rapidly generate two- and multiple-valent vaccines by incorporating SARS-CoV-2 mutants, SARS-CoV, or MERS-CoV.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , Animals, Genetically Modified , COVID-19 Vaccines/administration & dosage , Female , HEK293 Cells , Humans , K562 Cells , Macaca mulatta , Mice , Mice, Inbred C57BL , Mice, Inbred ICR , Primates , Specific Pathogen-Free Organisms , Spike Glycoprotein, Coronavirus/administration & dosage , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/immunology
15.
Immunol Lett ; 237: 33-41, 2021 09.
Article in English | MEDLINE | ID: covidwho-1293862

ABSTRACT

OBJECTIVE: In this study, we focused on the interaction between SARS-CoV-2 and host Type I Interferon (IFN) response, so as to identify whether IFN effects could be influenced by the products of SARS-CoV-2. METHODS: All the structural and non-structural proteins of SARS-CoV-2 were transfected and overexpressed in the bronchial epithelial cell line BEAS-2B respectively, and typical antiviral IFN-stimulated gene (ISG) ISG15 expression was detected by qRT-PCR. RNA-seq based transcriptome analysis was performed between control and Spike (S) protein-overexpressed BEAS-2B cells. The expression of ACE2 and IFN effector JAK-STAT signaling activation were detected in control and S protein-overexpressed BEAS-2B cells by qRT-PCR or/and Western blot respectively. The interaction between S protein with STAT1 and STAT2, and the association between JAK1 with downstream STAT1 and STAT2 were measured in BEAS-2B cells by co-immunoprecipitation (co-IP). RESULTS: S protein could activate IFN effects and downstream ISGs expression. By transcriptome analysis, overexpression of S protein induced a set of genes expression, including series of ISGs and the SARS-CoV-2 receptor ACE2. Mechanistically, S protein enhanced the association between the upstream JAK1 and downstream STAT1 and STAT2, so as to promote STAT1 and STAT2 phosphorylation and ACE2 expression. CONCLUSION: SARS-CoV-2 S protein enhances ACE2 expression via facilitating IFN effects, which may help its infection.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Bronchi/drug effects , COVID-19/virology , Epithelial Cells/drug effects , Interferon alpha-2/pharmacology , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/genetics , Bronchi/enzymology , Bronchi/virology , COVID-19/enzymology , Cytokines/genetics , Cytokines/metabolism , Epithelial Cells/enzymology , Epithelial Cells/virology , HEK293 Cells , Host-Pathogen Interactions , Humans , Janus Kinase 1/metabolism , Phosphorylation , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , STAT1 Transcription Factor/metabolism , STAT2 Transcription Factor/metabolism , Signal Transduction , Spike Glycoprotein, Coronavirus/genetics , Ubiquitins/genetics , Ubiquitins/metabolism , Up-Regulation
16.
Cell Death Differ ; 28(9): 2765-2777, 2021 09.
Article in English | MEDLINE | ID: covidwho-1195611

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is highly contagious and causes lymphocytopenia, but the underlying mechanisms are poorly understood. We demonstrate here that heterotypic cell-in-cell structures with lymphocytes inside multinucleate syncytia are prevalent in the lung tissues of coronavirus disease 2019 (COVID-19) patients. These unique cellular structures are a direct result of SARS-CoV-2 infection, as the expression of the SARS-CoV-2 spike glycoprotein is sufficient to induce a rapid (~45.1 nm/s) membrane fusion to produce syncytium, which could readily internalize multiple lines of lymphocytes to form typical cell-in-cell structures, remarkably leading to the death of internalized cells. This membrane fusion is dictated by a bi-arginine motif within the polybasic S1/S2 cleavage site, which is frequently present in the surface glycoprotein of most highly contagious viruses. Moreover, candidate anti-viral drugs could efficiently inhibit spike glycoprotein processing, membrane fusion, and cell-in-cell formation. Together, we delineate a molecular and cellular rationale for SARS-CoV-2 pathogenesis and identify novel targets for COVID-19 therapy.


Subject(s)
COVID-19/virology , Giant Cells/virology , Lymphocytes/virology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , COVID-19/pathology , Cell Line , Cell Line, Tumor , Giant Cells/pathology , HEK293 Cells , HeLa Cells , Humans , Jurkat Cells , K562 Cells , Lymphocytes/pathology , Virus Internalization , Virus Replication/genetics
17.
Sci Rep ; 11(1): 4432, 2021 02 24.
Article in English | MEDLINE | ID: covidwho-1101681

ABSTRACT

Cardiac injury is a common complication of the coronavirus disease 2019 (COVID-19), and is associated with adverse clinical outcomes. In this study, we aimed to reveal the association of cardiac injury with coagulation dysfunction. We enrolled 181 consecutive patients who were hospitalized with COVID-19, and studied the clinical characteristics and outcome of these patients. Cardiac biomarkers high-sensitivity troponin I (hs-cTnI), myohemoglobin and creatine kinase-myocardial band (CK-MB) were assessed in all patients. The clinical outcomes were defined as hospital discharge or death. The median age of the study cohort was 55 (IQR, 46-65) years, and 102 (56.4%) were males. Forty-two of the 181 patients (23.2%) had cardiac injury. Old age, high leukocyte count, and high levels of aspartate transaminase (AST), D-dimer and serum ferritin were significantly associated with cardiac injury. Multivariate regression analysis revealed old age and elevated D-dimer levels as being strong risk predictors of in-hospital mortality. Interleukin 6 (IL6) levels were comparable in patients with or without cardiac injury. Serial observations of coagulation parameters demonstrated highly synchronous alterations of D-dimer along with progression to cardiac injury. Cardiac injury is a common complication of COVID-19 and is an independent risk factor for in-hospital mortality. Old age, high leukocyte count, and high levels of AST, D-dimer and serum ferritin are significantly associated with cardiac injury, whereas IL6 are not. Therefore, the pathogenesis of cardiac injury in COVID-19 may be primarily due to coagulation dysfunction along with microvascular injury.


Subject(s)
Blood Coagulation Disorders/virology , COVID-19/blood , Heart Injuries/virology , Aged , Biomarkers/blood , Blood Coagulation/physiology , Blood Coagulation Disorders/blood , Blood Coagulation Disorders/epidemiology , COVID-19/epidemiology , COVID-19/physiopathology , COVID-19/virology , China/epidemiology , Cohort Studies , Creatine Kinase, MB Form/blood , Female , Fibrin Fibrinogen Degradation Products/analysis , Fibrin Fibrinogen Degradation Products/metabolism , Heart Injuries/blood , Heart Injuries/epidemiology , Heart Injuries/physiopathology , Hemoglobins/metabolism , Hospital Mortality , Humans , Male , Middle Aged , Risk Factors , SARS-CoV-2/isolation & purification , Troponin I/blood
18.
SciFinder; 2020.
Preprint | SciFinder | ID: ppcovidwho-4704

ABSTRACT

Our objective was to isolate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from nasal/throat swabs from coronavirus disease 19 (COVID-19) patients. Three nasal/throat swab samples from COVID-19 patients in Shanghai were treated with TPCK trypsin and inoculated Vero E6 cells in 96-well plates. When most of the cells showed obvious cytopathic effect, the supernatants of cell culture were collected and used to detect the viral nucleic acid by fluorescent quant. polymerase chain reaction (PCR) and amplify the gene fragment of the virus receptor binding domain (RBD) using reverse transcription-PCR. The replicated virus was inoculated into Vero E6 cells seeded in 96-well plates, the cytopathic effect was recorded by photograph and the viral proteins were detected by immunofluorescence method. The Vero E6 cells inoculated with two of three nasal/pharyngeal swab samples showed obvious cytopathic effect and newly synthesized viral nucleic acid was detected in the supernatants of cell culture. The amplified receptor binding domain (RBD) sequence was completely consistent with the corresponding fragment of SARS-CoV-2 isolated earlier. Virus-infected Vero E6 cells showed rapid cytopathy and can react with the monoclonal antibody against nucleocapsid protein (N protein) and spike protein (S protein) of SARS-CoV-2, and convalescence sera of COVID-19 patients. Two SARS-CoV-2 strains were isolated from nasal/throat swab samples of COVID-19 patients in Shanghai, providing the basis for the mechanism research on the infection and pathogenesis of SARS-CoV-2 as well as the development of drugs and vaccines against SARS-CoV-2.

19.
Academic Journal of Second Military Medical University ; 41(4):365-370, 2020.
Article in Chinese | GIM | ID: covidwho-829836

ABSTRACT

Objective To isolate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from nasal/throat swabs of coronavirus disease 19 (COVID-19) patients. Methods Three nasal/throat swab samples from COVID-19 patients in Shanghai were treated with TPCK trypsin and were used to treat Vero E6 cells inoculated in 96-well plates. When most of the cells showed obvious cytopathy, the cell culture supernatants were collected. We then detected the viral nucleic acid by fluorescent quantitative real-time polymerase chain reaction, and amplified the gene fragment of the virus receptor binding domain (RBD) by reverse transcription polymerase chain reaction. After amplification and culture, the virus was used to infect the Vero E6 cells inoculated in 96-well plates. The cytopathy was observed and the virus protein was detected by immunofluorescence. Results The Vero E6 cells that cultured with two of three nasal/pharyngeal swab samples showed obvious cytopathic effect and newly synthesized viral nucleic acid was detected in the supernatants of the cell culture. The amplified RBD sequence was completely consistent with the corresponding fragment of SARS-CoV-2 isolated earlier. Virus-infected Vero E6 cells showed cytopathies rapidly and could react with the monoclonal antibody against nucleocapsid protein (N protein) and spike protein (S protein) of SARS-CoV-2, and convalescence sera of COVID-19 patients. Conclusion Two SARS-CoV-2 strains were successfully isolated from two nasal/throat swab samples of COVID-19 patients in Shanghai, which provides evidence for the mechanism research on the infection and pathogenesis of SARS-CoV-2 as well as the development of drugs and vaccines against SARS-CoV-2.

20.
Academic Journal of Second Military Medical University ; 41(4):359-364, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-829835

ABSTRACT

Objective: To establish a method for preparing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudoparticles (SARS-CoV-2 pps).

SELECTION OF CITATIONS
SEARCH DETAIL